Resistance



M. w. wElscoPF 1,993,494

RESISTANCE March 5, 1935.

Filed Dec. 17, 1930 Patented Mar. 5, 1935 iUNITED STATES PATENT OFFICERESISTANCE Application December 17, 1930, Serial No. 502,917

'7 Claims.

The invention relates to a mounting for resistors.

One'of the objects of the invention is to provide a mounting forresistors on which the resistors may be quickly and easily assembled..

Another object of the invention is to provide a resistor 'readilyadaptable for mounting on a suitable support. Another object of theinvention is to provide a support for a plurality of resistors which isof strong and durable construction. Another object of the invention isto provide a mounting for resistors which may be produced at a low cost.Another object of the invention is to provide a mounting for resistorswhich substantially encases the resistors, so that they will not becomebroken even though subjected to rough handling.v Another object of theinvention is to provide a resistor gang construction readily adaptablefor use in a radio cabinet or in similar apparatus. Other objects willbe in part obvious or in part pointed out hereinafter.

The invention accordingly consists in the features of construction,combination of elements, and arrangements of parts, as will beexemplified in the structure to be hereinafter described, and the scopeof the application of which will be indicated in the following claims.

In the accompanying drawing, in which is shown one of various possibleembodiments of the mechanical features of this invention,

Figure 1 is an elevation of a single resistor before mounting,

liigure 2 is a longitudinal sectional view of the resistor, v I' Figure3 is a front elevation of the mounting for a gang of resistors with theresistors in position,

Figure 4 is a rear elevation of the mounting showing the resistors inposition.

Figure 5 is a cross sectional view of the mounting, the section taken onthe line 5,---5` of Figure 3a.

Figure 6 is an end View of the mounting,

Figure 7 is a perspective view of the mounting showing its rear orinside face without the resistors, and L Figure 8 is a view of one ofthe terminals used in constructing the resistors, x

Similar reference characters refer to similar parts throughout theseveral views of the draw- Referring first to .Figures 1 and 2, theresistor, which is indicated generally by the numeral 10, preferablyconsists of a rodor bar of porcelain or other insulating substance 11having a capillary passage 12 through which extends al resistanceconductor 13 embedded in metal end pieces 14. The resistance conductor13 preferably comprises a glass rod or filament covered with aconductive coating of high resistance material, such as carbon. Theconductor 13 is in intimate contact with the Wall of the capillarypassage 12, the diameter of the conductor being preferably as near tothe diameter of the capillary passage 12 as is practicable. Theporcelain insulator 11 is a good dielectric, so that there is no leakageof current through it, but as it readily conducts heat, any heatgenerated by the resistance element 13 is quickly dissipated.

The metal end pieces 14, 14 are rigidly connected to the porcelaininsulator rod 11. This may be done by relating the rod and theprojecting ends of the resistance conductor 13 which is supported by therod 11 to a suitable mold and molding the metal end pieces 14, 14 onsaid insulatingrod 11, thereby` embedding the ends of the resistanceconductor 13, Vas is clearly shown in Figure 2@ Preferably the metal end-pieces 14, 14 are of readily moldable metal, such as type metal, whichin cooling contracts and firmly grips the ends of the porcelain rod 11so as to form a firm and rigid body.

Referring now more particularly to Figure 8;

there are provided a pair of terminals 15 for each resistor 10, anexemplary embodiment of such terminals being illustrated in Figure 8. Asshown in thatI ligure, each terminal 15 comprises a portion ofrelatively large diameter 16 on one end of an elongated portion 17,there being a hole 18 in the portion 16 and a hole 19 in one end of theelongated portion 17. The portion 16, by reason of having included in itthe hole 18 which is comparatively large, is substantially an annulusmerging, however, into the elongated portion 17 in one end of which isthe hole 19 which is comparatively small.

The terminals 15 are desirably formed of sheet metal and may be madeinto the shape described by a stamping operation from a sheet or stripof material. The terminals 15 are desirably made of a good conductingmaterial, such as copper,

so that the resistance of eachresistor 10 may -be substantiallycompletely embodied in the resistance of the resistance conductor 13. Ifmade ofcopper, they may be coated with tin in order to prevent or retardcorosion. A further advantage of the use of copper for the terminals 15is that when bent they take a new shape and do not spring back intooriginal position,

and this is a desirable feature and assists in securing the separateresistors in position in their mounting, as Will more fully .appearhereinafter.v Other metal of relatively high conductivity and lowelastic limit might be sub.- stituted for copper inthe making of theterminals 15.

Inv the manufacture of the resistors 10 4a terminal 15 is related toeach end of the rod or bar 11 of insulated substance before the metalend pieces are molded. Referring now to Figure 2, the portions 16 ofrelatively large diameter of a pair of terminals 15 are placed againstthe ends of a rod or bar 11, the terminals 15 thus lying in parallelplanes, with the elongated portions 1'7 substantially parallel andtherefore projecting from the same side of the resistor being formed.The resistance conductor 13 extends, at its opposite ends, through thelarge hole 18 in each terminal 15. Type metal is then poured into themolds and completely embeds the portions 16, and when the type metal hascooled, the rod l1, the resistance conductor 13, the terminals 15 andthe metal end pieces 14 constitute an integral unit and the elongatedportions 17 of the terminals 15, which are flexible, ex-

tend laterally from this unit. Preferably theY annular portion 16 is,completely embedded in the type metal so that the metal end caps 14constitute a continuous piece, thus making the article exceedinglystrong.

rReferring now to Figures 3 to 7 inclusive, I provide a rectangularsheet of insulating substance 21. Preferably this substance is bakeliteor 'a phenolic condensation product which is strong, not brittle, has ahigh dielectric strength, and is not damaged by Water or oil. One of thefeatures of my invention is that the finished gang of resistors may begiven relatively hard usage Without being broken. In accordance withcertain features of my invention, other substances such as hard rubberand sheet ber might be used instead of bakelite.

Preferably the mounting for the resistance includes besidestherectangular sheet of insulating material 21 a pair of strips ofinsulating material, preferably bakelite, 22, 22. These strips 22, 22are fastened to the rectangular sheet 21 to form a generally channelshaped body 23 of insulating material. A plurality of resistors 10 areincluded Within the space contained Within this generally channel shapedinsulating body 423 so that the resistors 10 are well protected fromdamage during handling of these gang resistor units of the invention.

In accordance with certain features of the invention, I have devised avery effective way of connecting the strips 22, 22 on either side of thesheet 21 to said sheet. Referring to Figures 4 to 7 inclusive, a pair ofgenerally U-shaped pieces of flat metal 24, 24 are secured to the innersurfaces of the sheet 21 and the strips 22 respectively, extending alongthe end portions of said sheet. A hole is made near either end in eachstrip 22, and a corresponding hole is made in either leg of thegenerally U-shaped pieces 24. Also holes are made near the four cornersof the rectangular sheet 21, and corresponding holes are made in theconnecting portions of the U-shaped metal pieces, the several sets ofholes being s6 spaced that when the strips 22, 22 and the rectangularsheet V21 are placed together over a metal piece 24, the holes in thesheet 21 and strips 22 register with the holes in the fiat metal pieces.

The rectangular sheet 21 and the strips 22, 22

of bakelite or other insulating material are then riveted to thegenerally U-shaped metal pieces, therebeing a yU-shaped metal piece ateach end of the channel shaped mounting 23. This riveting is preferablydone by means of tubular metal fasteners 30, the tubular metal fasteners30 constituting hollow cylinders with an end flange 31. They may besimply placed through the registering holes, and then the end without aflange may be expanded by means of a suitable tool, which give thetubular fastener a second flange 32, and thus rmly encloses the metalpiece 24 and the rectangular sheet 21 or one of the strips 22 betweenthe opposite flanges of the tubular fasteners. This mode of attachmentof the U-shaped metal pieces 24 to the insulating material has thefurther advantage that the operation which produces the second angeactually presses the parts being fastened firmly together, and soproduces an article which is rigid at the joints. v

Referring particularly to Figures 3 and "I, a plurality of slots 33 aremade in the rectangular sheet of insulating material 21. In accordancewith certain features of my invention, these slots 33 are formed inparallel rows, with the slots of each row spaced similarly to the slotsof the other row, so that a pair of opposed slots are the same distanceapart and lines joining any pair of opposed slots are parallel.Referring now to Figure 4, a plurality of resistors 10 are locatedinside the channel shaped mounting 23 with their terminals 15 extendingthrough slots 33. Each resistor 10 has terminals 15 eX- tending througha pair of oppositely located slots 33, and as a result of the spacing ofthe slots in the manner shown the resistors are .parallel one toanother. The terminals 15 extend through to the outside of the channelshaped member 23, and said `terminals having been pushed through theslots until the metal end pieces 14, 14 are in direct contact with theback side of the rectangular sheet 21, the terminals 15 are then bentover in order to secure each resistor 10 in position. By this mode ofattaching the resistors 10 to the channel shaped mounting 23 theresistors 10 are firmly fixed to the channel shaped mounting 23, and maybe removed therefrom by bending the portions 16 of the terminals 15 sothat they extend at right angles to the axis of the resistors 10.

Referring now particularly to Figure 3, the portions 1'7 of theterminals 15 that extend through the slots 33 and the holes 19 in theseportions lie spaced from the mounting 23. One or more resistors may beconnected in any desired circuit by passing a conductor through theholes 19 in the opposite sides of said resistor. The conductors may besoldered to the terminals 15 at the holes 19, or the union may be amechanical one in which the resistance to deformation of the terminalspresses the metal thereof, particularly the sides of the holes 19,against the conductor. The terminals 15 thus comprise an effectivebinding post for the attachment of wire and at the same time theymechanically hold the resistors 10 in place in the channel shapedmounting 23.

The U shaped metal strips 24 each have a pair of laterally extendingportions 34 in which are holes 35 by means of which the entire unit maybe fastened either with nails, screws or any other suitable fasteners toa radio cabinet or other desired electric-apparatus.

Desirably the resistors 10 are of different reslstanoe value, so thatmany different resistance effects may be obtained from a single gangunit. The resistors 10 may be marked in any suitable manner to indicatetheir resistance value, and peep holes 45 are preferably provided inorder that the value of each resistor may be determined from eitherfront or back of the article. Separate resistance devices l may beconnected together in series or in parallel. The entire unit isextremely durable and owing to the fact that the separate resistors areenclosed and protected, as well as owing to the construction of theresistors 10 themselves and their attachment to an insulating body,there is no danger of a short circuit in the apparatus. One or moreresistors 10 may be removed from the channel shaped mounting 23 ifdesired.

It will thus be seen that there has been provided by this invention anapparatus in which the various objects hereinabove set forth, togetherwith many thoroughly practical advantages, are successfully achieved.

As many possible embodiments may be made of the above invention, and asmany changes might be made in the embodiment above set forth, it is tobe understood that all matter hereinbefore set forth or shown in theaccompanying drawing is to be interpreted as illustrative and not in alimiting sense.

I claim:

1. In apparatus of the class described, a rectangular sheet ofinsulatingmaterial, there being a row of slots near both sides of thesheet and the-rows being parallel, a plurality of resistors comprisinginsulating rods having therein resistance conductors, metal end caps onthe ends of the insulating rods, bendable metal terminals at each end ofeach resistor, said terminals having one end embedded in 'said caps andprojecting sideways from said caps, the terminals extending through theslots securing the resistors on the rectangular sheet in parallelrelation and providing for electric connection of the resistors incircuit with any apparatus, a lpair of rectangular strips of insulatingmaterial united to the aforesaid sheet and formingwith said sheet agenerally channel shaped insulating support for the resistors,` U shapedmetal pieces on the ends of the sheet of insulating material and of theaforesaid strips, being fastened to them and holding these three partstogether, and tubular metal fasteners securing the U shaped metal piecesto the sheet and to the strips of 'insulating material.

2. A resistor comprising an elongated body inl cluding a resistanceconductor, "a. generally^fiat.

piece of metal having anV annular portion at one end through which saidresistance conductor passes the plane of the metal being substantiallyperpendicular to the principal dimension of the projecting portion of'the resistance con-- ductor and'l said piece of metal having a lowelastic limit and a relatively high fusion point, and said dat piece ofmetal being irremovably secured to the elongated body, thexebysdaptmgthe resistor for attachment to a pdnel.

3. n apparatus of the class described, three sheets of insulatingmaterial, U-shaped metal pieces connecting said sheets together inchannel shape, tubular metal fasteners fastening the sheets to theU-shaped metal pieces, there being aligned holes in the central sheet,and a plurality of resistors having bendable metal terminals at each endthereof extending throug said holes.

4. In apparatus of the class described, a. plurality of resistors eachcomprising an elongated body, metal terminals permanently affixed to theends of said body and constituting electrical terminals of theresistance of said resistors, thin` flat bendable metal pieces includingan annular portion integrally attached to said terminals each having ,ahole for the attachment of a conductor, and a sheet of insulatingmaterial having slots through which said terminals are passed to securethe resistors to the material without-short-circuiting them orintercircuiting them.

5. A resistor comprising an elongated body, metal end caps on oppositeends of said elongated body shaped to exactly iit the ends' of 6. Meansfor mounting a resistor element onv an insulating support comprising acombined terminal, connection post and mounting member composed of sheetmetal formed to receive ,an end of the resistor elementand provided withan extension formed to receive a connecting conductor, said supporthaving an aperture through which a portion of the extension protrudes tobe bent over to secure the resistor element to the support.

7. Resistance apparatus comprising a `fiat panel made of insulatingsubstance and having two parallel rows of slots therethrough said slotsbeing elongated in the direction of the rows and` opposite slots beingpositioned in parallel lines, a plurality of cylindrical resistorbodies, metal end caps on the opposite ends of each ,resistor body infirm engagement with the cylindi'ical surface, flat metal terminal andmounting members one extending from each4 'end cap and integrallyattached to its end cap, the plane of the metal being perpendicular tothe axis of the resistor at the junction pointwith the cap and eachterminal having a low elastic limit anda lhigh melting point said fiatmetal terminal mounting members each extending through a slot and beingbent over to hold the resistors in place with the cylindrical end capstangent to the panel, and there being detents in the far ends of theflat metal terminal mounting members for the ready attachment of wiresby solder.

MARCUS W. WEISCOPF.

